Electrolytic technology utilizing dimensionally stable anodes (DSA) has been used for years for the production of chlorine and other mixed-oxidant solutions. Dimensionally stable anodes are described in U.S. Pat. No. 3,234,110 to Beer, entitled “Electrode and Method of Making Same,” whereby a noble metal coating is applied over a titanium substrate.
An example of an electrolytic cell with membranes is described in U.S. Pat. No. RE 32,077 to deNora, et al., entitled “Electrode Cell with Membrane and Method for Making Same,” whereby a circular dimensionally stable anode is utilized with a membrane wrapped around the anode, and a cathode concentrically located around the anode/membrane assembly.
An electrolytic cell with dimensionally stable anodes without membranes is described in U.S. Pat. No. 4,761,208 to Gram, et al., entitled “Electrolytic Method and Cell for Sterilizing Water.”
Commercial electrolytic cells have been used routinely for oxidant production that utilize a flow-through configuration that may or may not be under pressure that is adequate to create flow through the electrolytic device. Examples of cells of this configuration are described in U.S. Pat. No. 6,309,523 to Prasnikar, et al., entitled “Electrode and Electrolytic Cell Containing Same,” and U.S. Pat. No. 5,385,711 to Baker, et al., entitled “Electrolytic Cell for Generating Sterilization Solutions Having Increased Ozone Content,” and many other membrane-type cells.
In other configurations, the oxidant is produced in an open-type cell or drawn into the cell with a syringe or pump-type device, such as described in U.S. Pat. No. 6,524,475 to Herrington, et al., entitled “Portable Water Disinfection System.”
U.S. patent application Ser. No. 09/907,092 to Herrington, et al., entitled “Portable Water Disinfection System,” describes disinfection devices that utilize, in one instance, a cell chamber whereby hydrogen gas is generated during electrolysis of an electrolyte, and provides the driving force to expel oxidant from the cell chamber through restrictive check valve type devices. In this configuration, unconverted electrolyte is also expelled from the body of the cell as hydrogen gas is generated. In an alternate configuration in the same application, hydrogen gas pressure is contained in a cell chamber during electrolysis, but the pressure within the cell chamber is limited by the action of a spring loaded piston that continues to increase the volume of the cell chamber as gas volume increases. Ultimately, a valve mechanism opens, and the spring-loaded piston fills the complete volume of the cell chamber forcing the oxidant out of the cell chamber.
U.S. Pat. No. 7,005,075 to Herrington, et al., entitled “Gas Drive Electrolytic Cell,” teaches a disinfection device that incorporates an electrolyte solution and a gas head space within a closed electrolytic cell chamber. During electrolysis of electrolyte to a disinfectant solution, hydrogen gas is generated within the closed electrolytic cell thereby generating pressure within the closed cell. Upon completion of electrolysis of the electrolyte solution to produce the disinfectant solution, a discharge port on the electrolytic cell housing is opened. Gas pressure within the cell housing provides the motive force to expel all or most of the disinfectant out of the cell housing to such a point where the disinfectant solution is utilized. By definition, this device operates in batch mode.
Other inventions that utilize gas pressure generated from electrolysis are also described in the literature. U.S. Pat. No. 4,138,210, to Avedissian, entitled “Controlling the Pressure of a Gas Generator,” describes a gas torch that utilizes an electrolytic mechanism for generating and controlling pressure of hydrogen gas that is used as the feed gas for the torch. U.S. Pat. No. 5,221,451 to Seneff, et al., entitled “Automatic Chlorinating Apparatus,” describes a chlorine gas generating cell that operates at the same pressure as the treated water flow stream. Water under pressure flows through the closed cell and replenishes the electrolyte level in the cell. Partitions within the electrolytic cell maintain separation of the chlorine gas that is aspirated in the water stream. Chlorine and hydrogen gas generated within the cell maintain a pressure balance between the chlorine gas phase and the pressure of the liquid water flowing through the cell so that unconverted electrolyte is not drawn into the flowing water stream. U.S. Pat. No. 5,354,264 to Bae, et al., entitled “Gas Pressure Driven Infusion System by Hydrogel Electrolysis,” describes a system that generates and controls the production of oxygen and hydrogen gas in an electrolytic hydrogel process for the purpose of closely regulating the amount of liquid drugs that are delivered under gas pressure to the human body.
Inventions that use a gas bubble lift mechanism from boiling water, as in coffee makers, are also described in the literature. U.S. Pat. No. 4,331,067 to Mysicka et al., entitled “Coffeemaker”, and U.S. Pat. No. 4,744,291 to Wallin, entitled “Electric Coffee Maker” describe electric percolator type of coffee makers that utilize an electric heating coil with a check valve in the suction side of the coil. As water is boiled in the coil at the bottom of the coffee maker, the water vapor bubbles lift the liquid water up a tube to the top of the coffee maker. The check valve prevents back flow of the water in the coil. As the water is boiled out of the tube, water from a reservoir is gravity fed past the check valve to the heating coil thereby repeating or continuing the water heating cycle.
Commercially, batch type electrochlorinators are used to convert salt in a brine solution into sodium hypochlorite for the purpose of treating water. Such a device, in a carafe form is sold commercially by Cascade Design, Inc. Seattle, Wash. and is known as the SE200. The SE200 is powered from a separate 12 VDC source such as a car battery. The source of power can also be a solar panel, or line power converted to 12 VDC. To generate the brine to place in the device, the instructions call for using a measuring cup (provided with the device) to pour into the carafe, then to add water and stir until the salt is dissolved. The process of making the brine from dry salt can be time consuming and is another step that the operator has to use to complete the process.